.border_b1,.border_t1{position: relative}
.border_t1:before{
  border-top: 1px solid #e4e4e4;
  top: 0;
  -webkit-transform-origin: left bottom;
}
.border_b1:after{
  border-bottom: 1px solid #e4e4e4;;
  bottom: 0;
  -webkit-transform-origin: left bottom;
}
.border_t1:before,
.border_b1:after {
    content: '.';text-indent:-999rem;
    overflow:hidden;
    display: block;
    width: 100%;
    position: absolute;
    left: 0;
}

/* Retina 适配 */

@media only screen and (-webkit-min-device-pixel-ratio: 2.0),
only screen and (min--moz-device-pixel-ratio: 2.0),
only screen and (-o-min-device-pixel-ratio: 200/100),
only screen and (min-device-pixel-ratio: 2.0) {
  .border_t1:before,
  .border_b1:after {
        -webkit-transform: scaleY(0.5);
        transform: scaleY(0.5);
    }
}

/* 三倍屏 适配 */

@media only screen and (-webkit-min-device-pixel-ratio: 2.5),
only screen and (min--moz-device-pixel-ratio: 2.5),
only screen and (-o-min-device-pixel-ratio: 250/100),
only screen and (min-device-pixel-ratio: 2.5) {
  .border_t1:before,
  .border_b1:after {
        -webkit-transform: scaleY(0.33333334);
        transform: scaleY(0.33333334);
    }
}
